I tried several SD cards (all formatted with FAT32 and size between 1 and 32 GB) and all were recognized very well by M92 - especially no data loss. Neither have I read on this forum of such a bug.

Seems like something's wrong with your SD card. What does data loss mean in your case? Was the file system corrupt? Was the SD card unrecoverably broken? Or were there only several files that were deleted/corrupted/altered?